1. Field of the Invention
The present invention relates to video displays, and in particular, to video display controllers for controlling the signal and display characteristics of a video image.
2. Description of the Related Art
Video display units require some form of control for establishing and maintaining various video signal characteristics, as well as various image display characteristics. Such control can be of even more critical importance in the context of computer generated video images, particularly where such images involve detailed or complex graphical information. Additionally, video display units, or monitors, for computers typically include some form of on screen display (OSD) in which the various video signal or display characteristics to be controlled are listed along with some form of iconic information for aiding the user to make any desired adjustments by way of various control buttons on the housing for the display unit. The circuitry for such controls is typically included as part of the internal circuitry of the display unit itself, with some form of memory circuitry for retaining base parameter characteristics or values, while also allowing for retention of modified characteristics or value information following adjustments by the user of the display unit.
The use of such circuitry internal to the display unit itself has a number of disadvantages, not the least of which is costs associated with the design and manufacturing of such circuitry as part of the display unit. Additionally, while such circuitry may be made programmable, such programmability is limited in the sense that the user interface generally involves some form of mechanical or electromechanical switches on the housing of the display unit, thereby limiting the degree of programmability as well as the convenience of actually performing any programming steps through such switches. Accordingly, it would be desirable to have a more flexible technique for programming and controlling video signal and image characteristics of a display unit without requiring manual operation of mechanical or electromechanical switches as part of the user interface.